The roots decided the matter. They had a rough appearance due to a 

 great many black, hard cushions, differing in size and flattened into hemi- 

 spheres, which covered the upper surface. If treated with a solution of caustic 

 potash, when the tannin, occurring as a flocculent precipitate, turned a wine 

 red to brown, cross-sections show that the bark excrescences were covered by 

 a normal cork layer. The primar}' bark had developed parenchymatous ex- 

 crescences the cells of which, arranged in radiating rows, had colorless walls, 

 apparently dissolving with difficulty in sulfuric acid, and had a very firm 

 brown content. These bark excrescences were later cut off by an hourglass- 

 like, pl&te cork lamella, distending the outer cork layer, and were forced out 

 over the upper surface of the root as calluses by the subsequent growth of 

 the inner bark. The healthy bark was filled with starch. 



In the material sent me the branches had only very slightly raised bark 

 excresences, possibly 34 to ^ mm. broad, flattened and hemispherical. In 

 them was found the beginning of a many layered lenticel excrescence such 

 as had been obsen'ed in great numbers in the cherry with the tan disease. 

 The constitution of the leaves, still remaining on the branches, had already 

 indicated the diseased condition of the roots. They showed a browning and 

 dr)dng up of the parenchyma in the intercostal fields, extending from the 

 edge toward the mid-rib. Finally, the parenchyma was green only in the 

 immediate proximity of the ribs. The black, yellow-edged, roundish spots, 

 scattered over the sick leaves and containing various fungi colonies, musr 

 be considered as secondary phenomena. The condition found in the 

 branches in connection with the excrescences on the roots brings the disease, 

 which has been termed "Mai nero," into the group of the tan diseases. Ac- 

 cordingly, the choice of fibrous or good friable land which has a constant, 

 abundant soil ventilation will be the best precaution against the disease. 



The Rootblight of Sugar and Fodder Beets. 



As rootblight we designate a disease of the tissues which can set in 

 even when the young seedlings unfold their cotyledons or begin to open the 

 first leaflets. A black spot appears on the stem below the seed leaves which 

 spreads further toward the root end (less toward the cotyledons) and be- 

 comes depressed. Even if the young seedling has not reached the upper 

 surace of the soil, the first stages of the disease can be recognized. Vanha 

 observed that the tissue becomes glassy before turning brown. The little 

 plants begin to wilt and usually break at the diseased point. Death results 

 at once. If the disease is limited to a small area on the hypocotyledon stem 

 and the plant does not succumb, the depressed place will heal and a normal, 

 later growth follows. Because the diseased place blackens and often 

 shrinks to the size of a thread below the seed leaves the practical grower 

 also calls the appearance "black leg" or the "threads." The same term is 

 used as well in the blackening and softening of the hypocotyledons of cab- 

 bage plants, which arise, however, from other conditions. 



